Rotary pump machine



W. J. STERN ROTARY PUMP MACHINE Feb. 1,1927. 1,fi16,285

Filed se tfa 1925 10 SheetsShec-.t

9 192? w. .1. STERN ROTARY PUMP MACHINE Filed Sept. 9, 1925 10Sheets-Sheet 2 Feb. 1, 1927.

W. J. STERN ROTARY PUMP MACHINE Filed Sept. 9. 1925 10 Sheets-Sheet mmzwFeb. 1 1927.

W.,J. STERN ROTARY PUMP MACHINE Filed Sept. 9, 1925 10 Sheets-Sheet 4Feb- 19 mmzsa w. J. STERN ROTARY PUMP MACHINE Filed Sept. 9, 1925 10sheets-sheet 5 Feb, 1, 192?". 1,616,285

W. J. STERN RQTARY UMP MACHINE Filed Sept 9, v1925 1O Shee'fs-Sheet 6Feb, ii, 11%? 1,616,285

W. J. STERN ROTARY PUMP- MACHINE Filed Sept. 9. l925 lO Sheets-Sheet '7W. J. STERN Feb. 1, 1927.

ROTARY PUMP MACHINE 9. 1925 10 Sheets-Sheet 8 Filed Sept I Feb.1,1927..W J: STERN ROTARY PUMP MACHINE Filed Sept 9, 1925 10 Sheets-5heet 9 N.J. STERN ROTARY PUMP MACHINE Filed Sept.

9, 1925 l0 Sheets-$heet l0 rotor body has sliding rocking vanes. In

Patented Feb. 1, 1927.

UNITED'STATE'S PAT 7 ROTARY YUM! MAQHIEE.

Application flled september 9, 1925, Serial No. 55,295, and in threatBritain September 13, 192%.

This invention comprises improvements in rotary pump machines and isconcerned with the so-called crescent class of such machines. Moreparticularly, the invention is concerned with .pump machines of thecrescent class in which an eccentric piston or using these machines aspumps'or compressors, it is advantageousto drive the rotor, the vanesbeing connected with centric means such as a lay shaft and working inslots formed in cylindrical blocks mounted to oscillate in peripheralopenings in the rotor.

An im ortant object of this invention is to provid g for thereinforcement and better mounting of the vanes and to improve theirconnection with the centric means around which they move. 4

A further important object is to protect the vanes against unduestresses and wear andtear in their working engagement with the pistonbody or the oscillatory cylindrical blocks mounted thereon.

Yet another object is to construct vanes for the improved machine sothat such vanes have substantial thickness but are nevertheless lightand very strong and are adapted for resisting tip and edge leakage,thereby enabling the number of vanes employed to be reduced to aminimum.

Another object is to provide simple and eflicient lubricating means forthe vanes and particularly for the means provided in con 'nection withsuch vanes for relieving them of stresses as aforesaid.

Yet another object is to enable lubrication I to be largely curtailed byproviding antifriction mountings and bearings for the vanes andassociate parts.

These and other objects will be hereinafter fully described bv referenceto the drawings accpmnanying this specification and forming partthereof. such drawings illustrating examples of construction enlhodvingtl ese pre ent iniprorcments. In the drawings Figure l is an irre 'ul rlon itudinal secl P" l" ton on the line l-I of Figure 2 of a pumpmachine constructed in accordance with these improvements.

F igure 2 is a cross section on the line lI -II of Figure 1, looking inthe direction of the arrow parts being bro en away to show the centricgrooved ring, 0. v

Figure. 3 1s a central longitudmalsection and Figure 4 is a crosssection of a modified construct-ion of pump which is suitable for asmaller capacity than that possessed bytion on the line VIIIVIII lookingin the direction of the arrows, the rotor having been turned through anangle of 90.

, F igure'il is line IX-IX of Figure 10 which is a cross section on theline XX of Figure 9, these being fragmental views illustratinglubrication ducts formed in the end discs of the rotor.

Figure 1} is aplan view illdstrating a vane'constr' tion. somewhatsimilar to that 'seen'in Figures 1 and 2, one halt of a trunnion blockin which this vane works being also shown.

Figure 12 is a front elevation of Figure 11. the trunnion block being ,oinitted.

Figure 13 is a perspective View of a combined thrust member andsegmental shoe device for fitting to a vane.

Figure 14 is a central vertical section of a modified construction ofthrust member and shoe device.

Figures 15, 16, 17 and 18 are sections illustrating diiterent methods ofbuilding pp light vanes.

nion block and built up vane, vertical frame bars of the vane acting asthrust members tongue device.

are omitted from this figure and any suitable means may be used for thepurpose. Figure 20 is a perspective view of a frag ment of a modifiedsealing tongue.

Figure 21 is a perspective view of a plate which may be used for a builtup vane. A

Figure 22 is a perspective view similar to Figure 19 but showing amodified-construction of frame" bars'serving. aswthrust members. i j

Figure 23 is a central longitudinal fsection of a modified constructionof {pump with ball bearing mounting for the centric membersupon the laysha a horizontal section 'on the Figure 19 is a perspective view of atrunas seen in Figure 1. i

ill)

Figure 2% is a central cross section of the pump on the line XXIV-XXIVof Fig ure 23.

Figure 25 is a fragmentary view in perspective of the vane, centricmembers and lay shaft used in the machine illustrated in Figures 23 andE24, and

F igure 26 is a fragn'ientary View illustrating a modified method ofmounting the trunnion blocks or rockers'of the vanes.

Referring to Figures 1 and 2 of the drawlogs, or is -the cylindricalcasing of the pump clamped between end covers I) b by long bolts b Thiscasing may be jacketed if desired. Owing to the eccentricity'of therotor 0 a crescent space d is produced which is a characteristic of thisclass of machine. In the construction illustrated, the rotor o is a clindrical drum orbody carried by centre ly disposed discs or webs 0 on asleeve or hub d which is fixedly mounted on a, shaft 6 extending throughthe two end covers 6?). The drum rotor cisformed with "tour slots gspaced 90 apart, each slot heing enlargedhetiveen its inner and outeropenings to form a cavity to receive" an oscillatory cylindrical blockhhereinafter referred to as atrunnion block. Each of these trunnionblocks h is formed over the greater portion otits length between itsends with a diametrical slot for the reception of a slidable vane 3 Thevanes j are fitted with what are herein called thrust members i: k andin this examph; each vane is fitted with five such members uniformlyspaced. The three middle thrust members 7: are cylindrical rods or tubesslotted to receive the vanes and attached to the latter in the mannerhereinafter described. These members extend from the inner to the out-eredges of such vanes. The diameter of the members is L is greater thanthe thickness of the vanes so that portions of such members stand proudof the surfaces of the vanes j. The taro end thrust members 7: arelengths of tube or-rod slotted for a portion of their 5 th to receivethe vanes j and are carried toot portions Z formed on out side with pdevices 77? and on the other side with :m-uate projections or shoes nfor engagi g in annular grooves of rings 0 constituting the centricmeans as hereinafter described. The clip devices m are riveted to theextended inner portions of the vanes j Referring to Figures 11 and i2,it will be seen that the thrust membcrs lc may be carried at the ends ofa girder or stiffener" extending along the whole length of the inner endof the vane j, the arcual projections or shoes n being formed on theends of the girder or stiflener 32. As will be seen from these figures,the thrust members is are slotted to Within a short distance of theirouter ends so as to accommodate the vane j and the girder or stiii'cncrthe fixing of these members being effected by rivets which pass throughthe members 7) and the inner portion of the vane j. The

of sufiicien'tlength to permit the end portions of'the vane" to beinserted and then lifted therein to bring the unslotted end portionsinto the appropriate notches in the outer edge of the vane j. Ifdesired, the girder p and parts Z mm, may all be made in one piece andthe members Z" may be appropriately secured on the parts 7. In Figure 1,the girder p is indicated by a dotted line as it may or may not bepresent according to the degree of stiffness desired.

It is advantageous not to secure the clips m until the projections a areengaged in the centric grooves, a template representing the interior ofthe casing is then applied, and the vanes j are forced outwards bywedges inserted into the slots of the members In between the parts Z andthe vanes 7', and when the outer edges of the vanes have been adjustedinto sufiiciently close contact with the'template the clips m areriveted to the vanes.

As will be seen from Figure 11, the slots in the trunnion blocks h areformed with cylindrical recesses at the points corresponding with thedisposition of the thrust mem-- hers is is on the vanes, and the partsare so designed that the thrust members is have a closer sliding fit intheir recesses than the vaneshave in the slots. To reduce leakage theinner surface of the slots may be grooved. I

In the construction illustrated in Figures 1 and'Q, the centric meansconsist of grooved rings'o mounted on ball bearing 9 around theextensions 7 of eccentric bushings 8 containing the bearings of therotor shaft. That is to say the extensions r are concentric with theinterior of the casing a but the bushings s are eccentric thereto. Gapsz are cutout'or the rotordiscs (1 of such dimensions as freely to permitof the inward and outward sliding of the vanes 7' in'relation to therotor and'th'e limited oscillation ofsuch vanes 'j; 1

.ln OPGI'fltlOIl, the shaft eis driven by any suitable means and theeccentric rotor 0 through the medium of the trunnion blocks It carriesthe vanes j around the interior of the casing a. As the vanes have asliding connection with the centric rings 0 owing to the shoes n slidingin the grooves of such rings, there "will be a relative sliding of thevanes 5 inwards and outwards of the rotor "and in slots of thetrunnioablocks it Also, and for a reason well-known in the art, the vanes willoscillate from one side to the other of the truly radial position asthey perform'their orbits as will be readily understood from Figure 2.Thus, the rotor c and its vanes will produce suction through the ports uand delivery through the port v, or vice versa, accordingto thedirection in which the shaft is driven.

reaction between therotor c and vanes j is taken by the.thru'st'imenlhers k In tothe relief of the vane surfaces. owing to thefact above mentioned that the thrust members have a closer slidingvfitin their recesses than the vanes y'have in the slots in the trunnionblocks h.

lhe rotor 0, Figures 1 and 2, being slotted latter and retaining theblocks h in proper position. The said bearingsmay' be ball bearings andmay comprise a rotary and/or a ball end-thrust hearing as hereinafterdescribed with reference td' Figures 26 and 9. The rings on maystand"o't1t from the ends of the rotor andimayeun *ihgro gms a? in theend covers 6, b with fixed clearance.

The slide-Way gr'poves in the "rings dmay be lubricated by forcedlubrication through nozzles y. Other parts may be lubricated hv introducing' lubricant through a duct in the rotor lil) shaft. For example,in Figures 1 and 2,

a branch duct 2 communicates on the one hand with a duct or bore in therotor shaft and on the other hand with a groove 1 formed around the endof the rotor c. his groove which is closed by the bolting on of the ring'10 supplies the various trunnion hearings of the blocks h as will bereadily 'understood. This lubricating arrangement is shown only on theleft hand side of- Figure 1 but it would naturally be duplicated byl asimilar arrangement for the right hand s1 0. a

According: to the modification illustrated in Figures 3 and 4. theeccentric rotor shaft extends only just through the end cover 5 avhereit is fixedt'ti an end disc 2 at the left hand side of the rotor 0, theend at the right hand side of therotor being open and not closed-by adisc. The centric means in this example consists of a lay shaft 3intfoduced through and supported in the opposite cover 71. According tothis modification, the thrust In the revolu-' tion of the rotor c. thepressure due to the means.

members I: afford a. means of connection be tween the vanes j and thecentric means in the manner about to be described. The thrust members isare lengths of tube or hollow rod slotted from their outer ends foraportion of their length to receive the vanes j which are partly securedby the screwing in .of screw plugs [0 The thrust member 7:; in the lowerportion of Figure 3 and to the right of Figure 4 has its inner endscrewed direct into the lay shaft 3, whereas the thrust member win theupper portion of Figure 3 and to the left of Figure 4:, has its innerend screwed into a boss on a sleeve 4 revoluble on the lay shaft 3 andcircularly slotted for the first thrust member to pass through. sleeve 4are fitted with clips 5 which are riveted to the appropriatevane j whenthe latter has been adjusted into close contact with the interior ofthetcasing. Also, the shaft 3 is fitted with clips Gbeyond the ends ofthe sleeve 4 andthe clips 6 are riveted to the other, vane j seen in thelower portion of Figure 3. The shaft 3 beingmounted for revolution ,inanti-friction hearings in the cover I) and the sleeve 4 having only alimited oscillatory motion on the shaft 3 with which it revolves incompany, there is very little friction associated with the revolutionand oscillation of the vanes around the centric means. Theshaft 3 may betermed a master centric means and the sleeve at may be termedasubsidiary centric In the case of more than two blades being employed,there may be more thanone subsidiary centric means revolving with andoscillating upon the master centric means,

in order to minimize friction.

As'will be understood from-Figure 3, the disc 2 .of'the rotor revolvesin an eccentric cavity formed in the end wall or cover I and thecylindrical blocks h at one end er;-

tend into bearing recesses in the disc 2.

After the cylindrical blocks it, have been inserted into their hearingslots in the rotor 0 from the open end of the latter. a ring/w isapplied to the rim of such open end. the said ring" to being formed withhearings for the reception of the trunnion ends of the cylindricalblocks h as will be readily understood from Figure 3. The ring w runs inan eccentric annular groove formed in the coverb'. I

In the modification illustrated in Figures 5 and (3 the rotor c isattached by a disc 2 at one end only to a shaft ewhic'h extends throughone cover 7) only, the lay shaft 3 being introduced through andsupported in the opposite end cover b.- In this modification therearefour .vanes y and the centrio means comprises annularly grooved rings7 fixed on the re'voluble lay shaft 3, and the middle thrust members 70'are ex- ;tended inwardly and formed or fitted at their The ends of the Iinner ends with hub segments 9 having projections 8 for engagin with thegrooves of the centric rings 7. T 1e lay shaft 3 may be formed with anoil duct supplied with oil by a suitably arranged pump 10 lateral ducts11 providing oil for the lubrication of the grooves in the rings 7. Atube 12 is connected between the inner end of the shaft 3 and a bearingcap, not shown, on the rotor shaft. Thus, a duct 13 in the rotor shaftis supplied and branch ducts 14 leading from the duct 13 may deliverlubricant to the trunnion bearings of the blocks h or to other parts asdesired. The modification illustrated in Figures 7 and 8 is in somerespects similar to that illustrated in Figures 8 and 4. In the upperportion of Figure 7, however, it will be seen that the inner end of thethrust member Z: is connected with a sleeve 15 revoluble on the layshaft 30. There are two thrust members it for the vane in the lowerportion of Figure 7 and these have their inner ends attached to rings 16revoluble on the sleeve 15. Thus, inasmuch as the sleeve 15 and rings 16mainly rotate in company, only the friction between the sleeve 15 andthe lay shaft 30 comesinto consideration assuming that the lay shaft 30is fixed. Howeventhe lay shaft may be revolubly mounted. If more thantwo vanes were employed, the centric ring or sleeve of one of them couldbe arranged to revolve on the lay shaft like the sleeve 15, and thecentric rings 15 or sleeves of all other vanes could be revoluble on thesleeve 15 so as to avoid friction losses by friction on the shaft 30.

For lubricating the parts. the lay shaft 30 may be formed with oil ducts17 and these may be supplied from a pressure sup.- ply, s for exampleanoil pump diagrammatic lly indicated at 18. Branch ducts radieting fromcentral duct may supply lubricant to the interior of the sleeve 15 andalso to the bore of the thrust members 10.

lhe said bore may be stopped before the outer end is reached and aradial hole formed communicating with the bore at a point in the lengththat reciprocates through the cylinder block it. In this way, lubricantis supplied in a very simple and eliicient mcnnor to the thrust membersand their bearing surfaces, as will be readily understood.

To prevent or minimize end leakage past the rotor, the latter may belifted at its ends with small paddles or vanes 19 which are engaged toset up a pressure at the ends of the rotor 0 in such a manner asto'discourageleakage past the ends of the rotor. These paddleswill bevery light and may be allowed to rub under centrifugal action in thefixed clearance space of the rotor end ringe- Accoidmg to Figure 9, thetrunnion block ruwluchmay be to those seen in Figures 1 and 2, forexample, has its ends received in bearing bushes 31 secured in suitableapertures in the ends of the rotor the said bushes also containing endthrust" ball bearings 32 for the ends of the blocks h. The rotor may beof the kind compris-- ing a disc 0 at. each end and oil ducts 33 may bebored out through the thickness of these end discs 0 The bushes 31 maybe perforated as shown at 34c to admit the oil from the ducts 33 forlubricating the ends of the blocks h. The blocks It may be formed withoil grooves or ducts 35 for conve ing the oil along the blocks h fromthe end bearings to radial passages through which some of such oil willpass into the recesses in which the thrust members it slide foreffecting lubrication'of such members and also through side ducts tolubricate the surfaces of the blocks h and the vanes j' where theycontact. Figure 10 shows the oil ducts 33 aforesaid in coni'iection witha bore in the rotor shaft, through which bore oil from a pump may beconveyed as aforesaid.

Figure 14: illustrates in detail a convenient mode of securing the vanesj to the thrust members or tubes it. According to this mode ofattachment, the tube 7: is formed with a taporing slot from its innerend to near ts out.- er end, the wider end of the slot being at theinner end. The vane 51' is made with a tapering cross-section tocorrespond with the slot and it is formed with a notch in its outer edgeso as to enable such outer edge to come flush with the end of the thrusttube. as will be understood from Figure let. lVhen the vane 7' has beenintroduced into the slot, a screw threaded socket 20 is screwed on tothe screw threaded inner end of the thrust tube 72 and locks the vane inthe tube. the socket being formed with projections 21 for engaging withgrooved centric means such as have been hereinbefore described.

Figure 15 illustrates a vane made up of sheetmetal plates 22 attached bywelding, soldering or other means to a frame 23. In the exampleillustrated, the outer and side edges of the frame are ribbed at 2d forthe purpose of preventing or n'iininiizing side edge and tip leakage ofthe pressure fluid past the vanes. Thrust members of any of the kindsherein described are applied to vanes of this construction, orn'ielnbers of the framing 23 may be adapted for serving as thrustmembers as hereinafter described\.

Figure 17 shows how a vane can be built up of a plurality of thin metalsheets each separated from its neighbour b wires or rods 26, the sheetsbeing welded to the wires and thereby giving a very light constructionpossessing greatstrcngth and stiff ness.

Figure 18 shows a vane consisting of a plate 2? of light metal or alloysuch as aluminium or aluminium al' frame 28 those recesses whereas andother cross sections may reraa'ss yeast within a of steel or-other metalpossessing strength. The members of this framing are adapted for servingas thrust members as hereinafter described.

In Figure 16 avane of sheet metal is formed which not only impartstrength at which, in passing through the slot in the trunnion block htend to prevent leakage of. pressure fluid through such slot owing tothe labyrinth effect .produced. I

The separate thrust members may be segments of tubes or plates attachedto: respective surfaces of the vanes as by welding for example. It isnot necessary for the thrust members to be cylindrical or of circular orcurved cross section but rectangular be used- For example, in Figure 19abuilt up vane is' composed of spaced plates 40 inserted-into grooves ofvertical frame members 41, so that the plates fill :the spaces betwensuch'frame members. The vertical members 41 are connected at thev innerends with a transverse bar or member 42 which serves as the girder orstiffener erence to Figure 12. The inner ends of the plates 40 mayextend into grooves in the bar 42 and be rivetedtherein as shown. Thetrunnion block I isformed with a slot for the passage of the plateportions of the vane and this slot is enlargedto form rectangularrecesses for the passa e of the. frame members 41. The latter ave asliding fit in the plates 40' pass freely through the slot. structiontheframe" members t1 serve as thrust members to take the stresses due toVanes need 'not make such contact themselves. For this purpose, theouter edges of the vanes would be formed with agroove for receiving asealing tongue which could be adjustahleinwardly and outwardly of suchgroove, or the said tongue could be insorted in such groove so as to befree to move-radially outwards under centrifugal action and thereby makesealing contact with the casing." In Figure 19, the hollow space in thevane between the parallel plates 40 accommodates a sealing tongue 43where as a solid vane would require to be formed with a groove orchannel along the outer' edgeport'ion to receivesuch tongue. The tongue43 mayv be ofsheetmeta] formed. with with horizontal corru ations 29 phereinbefore described with ref- 1n Figure l 22,

Thus, in this con- 'nal cavities 'ing 56 mounted in 'a a roll or head44. By forming a sort of keyhole slot in the outer ends of themembersfll, the tongue 43 can be passed in endwise, as will beunderstood from Figure 19,

and-secured by screwing the screw 45 into" the counter. sunkscrew-threaded hole 46. The tongue would be cut accurately as to vidthso as to have sealing contact with the interior of the casing. thetongue might have a certain freedom for moving outwards undercentrifugal action, or it might ,be engagedby anadjustment for moving itinwar ly or outwardly of the vane,

as will be readily understood.

Fi ure 20 shows a'sealin tolwue with a b b b thickened edge portion oftriangular cross section in place of the roll or head 44. If desired,the sealing tongues may be of curved v These plates may belinserted gagerecesses at the ends of the slots so as. to fix the positions of theplates which are then secured by rivets or screws passed through the bar42.

According to the modification illustrated 'diagonalframe bars 48 areused as thrust members in place ofthe middle bar 41 in Figure 19 whichis parallel with the end bars 41. In this case, the slot in the trunnionblock is-of proper Width all along to give a sliding fit with all thethrust members. Thus,it will be appreci-. ated that the thrust-membersare capable of'taking a number of different forms without departing fromthis invention. 7

The modified form of pump shown in plate 40 formed.

If desired, however,

in the bar 42 into the position Figures 23, 24 and 25 comprises a layShaft 3 fixedly mounted in one end cover I) of the go, the shaft beingheld against pump casin rotat ion. by a key 49.

The rotor 0 comprises a shaft e and a frame consisting of a disc.

50 at one end and. a ring 51 at' the other joined by four bars 52. -Thcshaft 6 and the said frame, may be made from a single piece of steelsuitably machined to form the parts mentioned. The bars are recessed forthe mounting of segmental plates'53 which complete the rotor body.struction imparts rigidity to the rotor and renders itof appreciablylight weight. The trunnion blocks 72. are received in g in the bars 52;and ther trunnion ends may bear in plain recesses 54 in the end disc andring of therotor, or as shown by Figure 26, they may turn in ballbearings 55 dis 'sed'in the recesses 54 in the end disc an body. The layshaft 3' issupported at its end remote from the cover. 5 by a. ballbearcirg'u'lar recess in the This conlongitudiring 50 and 51 ofthe rotorlit end disc 50 of the rotor and having its inner race formed on aneccentric member 5'? which is lXlfU'fEtlflll to receive the end of the,lay shaft.

The end of the rotor adjacent the end cover ot the pump cusin issupported by :1, similar hull hearing 58 on. the lay shaft 3. The runesj are of somewhat similar construction to the vane shown in Figure 19hut instead of the plates a l) being mounted in grooves in the verticaland girder members 41 and respectively these former on opposite sides asat til, Figures 23 and 25, so that they meymove on hull bearings 62mounted in the trunnion blocks, see Figure The trunnion blocks Ii rosybe lubricated at their hearings in the parts 50, end 52 by lubricantsupplied from an annular groove 63 in the disc '50 and grooves 64:running along the rockers. The groove 63 is supplied by passages G l inthe disc 50 from u chamber 65 bit the centre of the disc, this chamberin'turn being'fed from an axis-ll duct 66 in the lay shaft 3. Thisprovision for lubrication of the roclrers k, may, however,.he dispensedwith it the rockers be mounted in hell bcnringsot'i as shown in Figure26; in that case slight clearance would he allowed between the 'cylindrical surface of the rockers and the corresponding surfaces in theslots 9 in the bars 52 of the rotor body. friction in the revolution ofthe vanes j and to do away with necessity for lubrication at the layshaft, these vanes may be mounted on centric ring members 61' whichrotate on ball bearings $8 on the lay shaft. "lhe centric members haveT'sheped slots 69 for the mounting of the vanes j and the latter ereformed along the inner longitudinal edge with lateral rojections or feetportions 70 to engage t 1e slots as will be readily," understood fromFigure 25.

vanes altogether in the machine shown in Figures 23, '24 and 25 andtwelve centric members 67 all of the same construction. This allowsthree centricuiernhers to each .vone end as successive centric lin s aremade to support successive Vfil13S,tl1l?lT8BCfitflC rings of each vaneare spaced apart equh distantly and thus support the vanes evenly.

In the above-mentioned constructionsin Figures 23 to 26, it is obviousthat roller" 7 v thrust members having sliding engagement hearings maybe substituted for any oil-"ell of the hull hearings therein shoWn. Bullbearings 32 for telling end thrust on the engines. themselves are notsub JQClIQOl to any mechanilln order to avoid There are four rockers mayalso. he provided as in Figure tion, it will he understood that otherformer lions having trunnion ends may be employed provided they areadapted for afi'ording e sliding fit or hearing for the thrust inemhers.

The improved pumps are particularly adapted for use us blowers for theintroduction of whet are known as superchnrges into the cylinders ofinternal combustion Ewing to the fact that the vanes cnlwenr and tear,they can he run efficiently at high speed and large eccentricity and inView of this the blowers are Well eds ted for use v on aero engines andthe like. Z owever, the blowers llIQ also well adapted for use inconnection with vacuum cleaners and other apparatus in which-sir isrequired to be moved for creating a pressure or e vacuum es the case mayhe.

Heretoi'fore, it has been customary to use thin steel rnnes to securelightness in this type of machine, but the disadevnntege oi using thinblades is obvious where high speeds large eccentricity and substantialpressures are concerned. Venes 0i sufi'ieient strength and stiffness forsatisfying the Working re uirements in the presence of such speeds anpressures were calculated to make the machine too heavy and cumber-"some and to create undue wear and tear and dill'iculties in WOTkIYIg.

ness may be secured'hy adopting :1 light built; up rene and such vanesare made wholly satisfactory for the aforesaid working condit ons by theprovision of the thrust members having the functions hereinlieforedescribed, llith vanes of SllbShUll-llllllllt ness'side edge .and tipleakage is reduced and suchvunes lend themselves more readily than thinblades to the application ofsusiliaryriueans for the further preventionof such, leakiige. V I

Iclaim -r-H.

1. Rotary pump machine comprising in combination e cylindrical casing-aneccem trio vpiston body rcvoluble therein, rockersdisposedparellel.with the axisof'said piston endrockaloly mounted inslots formed in the periphery of said piston, vanes-pessingfreelythrough slots in said rockers, contric ineiins mounted in saidcasing and engaged said vanes, and thrust members in operativeconnection with; said vanes, said with 'su'id rockers and being adaptedto trsnsnnt to ssid rockers the reactionary combination a cy thrustmembers constructed I said rockers,

mam

forces developed during the working oil-said VaheS.

2. Rotary pum machine comprising-in ndrical casing, an eccenrevolubletherein, rockers disposed parallel with the axis of said piston androckably mounted in slots formed in the periphery of said piston, vanespassing freely through slots in said rockers, centric means in saidcasing and operatively engaged by said vanes, and thrust membersconnected with and standing proud of the two surfaces of said vanes andhaving sliding engagementwith said rockers, said thrust members beingadapted for transllnita ting to said rockersthe reactionary foncfideveloped during the working of saidvan S.

3. Rotary pump machine comprisin tric piston body tric piston bodyrevoluble thereln, rockegsQ disposed parallel with'the axis ofsaid pis;ton and rockably mounted in slots formed in the periphery of saidpiston, vanes passing freely through slots in said rockers, centricmeans mounted in said casing, andto act as holders for said vanes and to,be' engaged with said centric means, said thrust members havin slidingengagement with said rockers and being adapted'to transmit to saidrockers the reactionary forces developed during the working of saidvanes.

4. Rotary pump machine comprising in combination a cylindrical casing,an eccentric piston body revoluble therein, slotted rockers mounted inperipheral slots in said body, vanes passing through the slots ofcentric guides in said casing and cylindrical stiffeners on aidv'anesextending from the inner to t e outer edges thereof, said stiflenersbeing adapted for sliding in the slots in said rockers and therelyrelieving the vanes of working stresses substantially as set forth.

5. Rotary pump machine comprising in combination a cylindrical casing,an eccentric piston body revoluble therein, slotted rockers mounted inperipheral slots in said 'bod vanespassing through the slots of sairockers, centric guides in said casin cylindrical stifleners on saidvanes extending from the inner to the outer edges thereof, saidstifieners being adapted for sliding in the slots in said rockers andthereby reliev'ing the vanes of'working stresses, and

3 means on said stiffeners in engagement with said centric guidessubstantially as set forth,

6. Rotary pump machine comprising in combination a cylindrical casing,an eccentric piston. body revoluble therein, vanes working in and-out ofsaid piston body through slots in the latter during a revolution, thrustmembers on said vanes said members taking a bearing in the said slotsand relieving the vanes of working stresses,

i combination a cylindrical casing, anteccena centric means revolublymounted within the casing, and operative enga ing means between saidvanes and sai centric means substantially as set forth.

7. Rotary pum machine comprising in combination a cy indrical easing, aneccentric piston body revoluble therein, vanes working in and out ofsaid piston body through slots in the latter during a revolution, thrustmembers on, said vanes said members taking a bearing in the said slotsand relieving the vanes of working stresses, centric meansrevolubly-mounted within the casing, and foot devices connected withsaid wanes and having operative en agement said centric meanssubstantially as set 0 H; 1. i

8. Rotary pump machine comprising in combination a cylindrical casing,an eccentric piston body revoluble therein, vanes working in and out ofsaid piston body through slots in the latter during a revolution, thrustmembers on said vanes said members taking abearing in'the said slots andrelieving the vanes of working stresses, centric means revolubly mountedwithin the casing, and foot devices connected with said thrust membersand. having operative engagement with said centric means substantiallyas set forth. i a

9. Rotary pump machine comprising in combination a cylindrical casing,an eccentric piston body revoluble therein, vanes working inand 1 out ofsaid piston body through slots in the latter duringa revolution, thrustmembers on members taking a bearing in said slots and relieving thevanes of working stresses,

within the casing, with said thrust and foot devices connected membersand with. said vanes and having engagement with the grooves in saidcentric as set forth.

10. Rotary pump machine comprising in combination a cylindrical casinganeccentric cylindricpiston revoluble therein and with an annular end ofsaid piston running in an eccentric groove formed in an end wall of saidcasing, slotted cylindrical rockers disposed in slots formed in saidpiston parallel with the axis thereof, an end ring on said piston saidretaining said rockers in their slots and also for acting as a runner in the eccentric groove in aid end Wall, reinforced vanes working in t eslots in said rockers, and centric means mounted within said casing andhaving operativeengagement with said vanes substantially as set forth."

11. Rotary pump machine comprising in combination a cylindrical casing,an eccentric means substantially ring being adapted for cylindricalpiston revoluble therein, slotted.

of substantial l hiclmess slidaljle radially of said casing in the slotsof said rockers, cyliiidrical sigiil encrs having a, diameter which isgreater than the thickness of said aid stiii'eners being attached tosaid vanes and slidable rarlisliy of the casing in enlargements of slotsin said rockers, centric means mounted Within said casing and operativemeans engaging between said vanes and said centric means substantially12, lioiary pump machine comprising" in Main 7 ion a cylindrical casingan eccentric '1': piston reroluhle llicrein packing means on the coilsoi said piston adapt-ed for (Jo-operating with. the end Walls of saidcasing for prorenting end leakage past said piston, sloliied cylindricalrockers disposed slots in said. piston parallel with the axis iircof,reinforced vanes Working in the slels of said rockers, centric meansmounied Wil-hio said casing, and operaiive means enbetween said vanesand said centric means substansially sell forth.

Rotary pump machine comprising in combination a cylindrical casing, aneccentric piston body rsvolubie therein, vanes slidably and IOCiKZLlJlfmounted in slots in sold body, acentric shall inounaed in said casing,centric members encircling saidshsft and having engagement with saidcones for producing motion of said wanes in said slots, andanti-friction bearings inserted between said centric members and saidshaft, sulr sliantially as set forth.

"iotar pomp machine, comprising in combination a cylindrical casing, aneccentric pislzon hody re'voluahle iiieieii'i vanes slidalri androehaoly mounted in slots in said body, a centric shaft mooni ed in saidcasing,

cenliric ring members encircling-said shaftand having engagement withsaid vanes for producing motion of said vanes in said slots, and boillies-rings ins ed between said centric embers said shelf. suhpumpmachine comprising; in. con "iination cylindrical casing, an eccenlriccylindrical piston. body revoluole therein, canes slidalil r androchahly mounted in slols in said body, a cenlric lay shaft with fixedhearing one end in said casing, an,

eccentric disc on the olher end of said lay shaft, anli-iiricsionalbearing means sup ported by said disc and e a-operating with aco'ocenlric bearing of said. piston body, and centric members encirclingsaid shaft and heroic engagement with said vanes for producin; alivemotion ihcreol in the slols of the ii body sulasl'antially as sci forth.

i'loiary pomp machineicornprising in combination a cylindrical casing,an eccentric oislou heal revoluble therein, vanes slidably and rockahlXllULl'lliMi inslors in said body,

release reinforcing means on said vanes adapted for relieving the vanesoi the r-orking stresses, a centric shaft rigidly mounted in saidcasing, ccnlric ring members rcvolulilc about said shaft and havingengagement Willi said reinforcing means and hall hearings insertedbetween said centric ring members and said sllafl substantially as setforth.

l7. Rotary pump machine comprising in combination a cylindrical casing,an ccccnirio vanes passing" llirougli the slots in saidroclr'e'rs,reinforcing memhcrs for said vanes, ball bearings inserted in saidrocker slos on either side of the vanes and in engagement' withsaidreinforcing members and centric means rev'olubly-mounted in said casingand having engagement with said reinforcing members of thevancssubsfanlially as set forth.

Ll. Rotary pump machine comprising in combination a cylindrical casing,an eccentrio piston body rcvolnble therein, slotted rockers mountein=peripheral slocs in said body, hearing members in said body fortaking end thrust on said rockers, vanes slidably mounced in the sloisin said rocker and centric means xevolubly mounted. in said casing andhaving=-engagemcni; with said vanes for producingmiaion said vanes inihe slois in said rockers suhslanl'iaily as set forth. I

Q0, Rotary pomp machinecomprising in combine-lion a cylindrical casingan eccentrio piston bod revoluble therein, s'ioite'cl roclrcrs mounts inperipheral slots in said body, thrust ball bearings mounted in said bodyat the ends of said rockers, vanes siidably mounted in the slots in saidrocker and centric means re'volu'oiy mounited in sai casing and havingengagement wish said vanes for producing motion of said vanes in theslots in said rockers substantially as set forth. i

increase in said casing and having engagement with said vanes forproducin motion of the vanes in the slots in said roe ers substantiallyas set forth. a

22. Rotary pump machine comprising in combination a cylindrical casing,a piston body eccentrically and revolubly mounted in said casing by ashaft at one end and a ball bearing at the other end, a lay shaftcarrying said ballv bearing and mounted rigidly by one end in a centralposition in said casing, a ball bearing adapted for supporting the saidshaft eccentrically in said piston body at its other end, vanesslidably, and rockably mounted in slots in said piston fbody, andcentric members revolubly mounted on said shaft and having engagementwith said vanes substantially as set forth.

23. Rotary pump machine comprising in m combination a cylindricalcasing, a cylindrical piston body mounted eccentrically and revolubly insaid casing by a shaft at one end of said body and a ball bearing at theother end, a lay shaft carrying said ball bearing and mounted rigidly byone end in a central position in said casing, a ball bearing adapted forsupporting the said shaft eccentricall y in said piston body atits'other end, slotted rockers disposed in peripheral slots in saidpiston body, ball bearings mounted in said body for the rockablemounting of said rockers, vanes passing through the slots in i saidrockers, reinforcing members for said vanes, ball bearings inserted insaid rocker slots on either side of the vanes and in engagement withsaid reinforcing members,

centric ring members mounted on ball b ear piston body, the stresses dueto reaction during operation being thereby localized on the thrustmembers which are calculated to Withstand such stresses to the relief ofthe vanes. v v

25. In a. rotary pump machine of the character described and in whichthe vanes are subject to acceleration and deceleration during arevolution of the piston body at uniform speed, the combination withvanes of light construction and substantial thickness of thrust members,possessing relatively great strength and rigidity, said mem bers aving asliding fit in rockable means on said piston body and said vanes beingfreely slidable and rockable in slots in the iston body, the stressesdue to reaction dur ing operation being thereby localized on the thrustmembers which are adapted for withstanding such stresses.

W. J. STERN.

